A longitudinal study on growth in untreated children with Angle Class II, Division 1 malocclusion.

The aim of this longitudinal study was to analyze growth-related changes in untreated Class II, Division 1 subjects. Forty untreated Swedish children with Angle Class II, Division 1 malocclusion were cephalometrically examined. The average age of the total group was 10.1 years at the first examination and 12.0 at the second. In addition to statistical comparisons of the average values of variables at both time points, multivariate analyses (harmony box according to Hasund and Segner, regression equation analyses) were also performed. This permitted individual evaluation of skeletal structures, position of incisors, and the soft tissue profile relative to the given craniofacial configuration. With the ANB angle remaining unchanged, both jaws were transposed ventrally. The reduction of the angle between the palatal and mandibular planes and the gonial angle was accompanied by anterior rotation of the mandible. The lower incisors protruded, and upper and lower first molars exhibited a translation to ventrocaudal. According to harmony box analysis, the most frequent cause of a distal relationship between the 2 jaws was a disharmoniously anterior shift of the maxilla. This was confirmed by the additional analysis of the available unpublished raw data from untreated Norwegian and Munich Class II/1 subjects and from other studies. In such cases, orthodontic treatment methods exerting a growth-inhibitory effect on the maxilla should be used.